8. Fair Value: Fair Value Measurements, Nonrecurring (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Impaired Loans
Assets, Fair Value Disclosure, Nonrecurring	$ 76	$ 134
Other Real Estate Owned
Assets, Fair Value Disclosure, Nonrecurring	392	626
Fair Value, Inputs, Level 1 | Impaired Loans
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Inputs, Level 1 | Other Real Estate Owned
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Inputs, Level 2 | Impaired Loans
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Inputs, Level 2 | Other Real Estate Owned
Assets, Fair Value Disclosure, Nonrecurring	0	0
Fair Value, Inputs, Level 3 | Impaired Loans
Assets, Fair Value Disclosure, Nonrecurring	76	134
Fair Value, Inputs, Level 3 | Other Real Estate Owned
Assets, Fair Value Disclosure, Nonrecurring	$ 392	$ 626